Universal transfer file for dvd

ABSTRACT

This invention relates to a method for creating a transfer file, the file comprising an information block comprising information on a data block and the data block comprising a navigation field and the navigation field comprising a Relative Logical Block Number of the navigation field, the method comprising the steps of creating a transfer file by appending the data block to the information block, to a method for recording such a transfer file, to a playback device and to a recording device.

This invention relates to a method for creating a transfer file, thefile comprising an information block comprising information on a datablock and the data block comprising a navigation field and thenavigation field comprising a Relative Logical Block Number of thenavigation field, the method comprising the steps of creating a transferfile by appending the data block to the information block, to a methodfor recording such a transfer file, to a playback device and to arecording device

At present the DVD standard has introduced a standard format for storingdata streams on an optical recording disc. For storing video streams theDVD+VR standard defines a structure in which the necessary informationfor playing back a video stream is stored on a DVD disc.

Now that a recordable and rewritable DVD disc is available the transferof sections of a data stream from one device to a device able to recordthis data stream is becoming an important issue.

The data stream on a DVD disc is stored in a VTS block. This VTS blockcomprises a VTSI block which is an information block where informationrequired for the proper playback of the data stream is stored. The VTSblock further comprises a VOB block in which the actual data stream isstored. The VOB block comprises one or more VOBs and each VOB in turncomprises one or more VOBUs. For navigation purposes each VOBU comprisesa navigation field from which the player can retrieve information aboutthe VOBU, for instance during trick play.

The navigation field comprises an entry where the logical block numberof the navigation field is stored.

When a section of a data stream stored in a VTS block is transferred toanother device the data stream is retrieved from the VOB block using theinformation stored in the VTSI block. The data stream then no longercomprises any information previously stored in the VTSI block ornavigation fields. A completely new VTS block is created where the VTSIinformation and the navigation fields are recreated based on theprocessing of the data stream for creating a new VTS block for transfer.

This has the disadvantage that when creating a new VTS block suitablefor transfer to another device any embedded information that wasembedded in the VTS block is lost and a complete processing of the datastream to create a proper new VTS block must be performed, requiringsubstantial processing power.

It is the objective of the present invention to overcome thedisadvantage and provide a method for creating a new VTS while avoidingthe loss of embedded information and lowering the processingrequirement.

To achieve this objective the present invention is characterized in thatin the transfer file the Relative Logical Block Number of eachnavigation field in the data block is recalculated relative to a firstLogical Block Number of the data block in the transfer file.

Instead of extracting the data stream, the VOBUs of the VOB block areleft intact and only the single entry of the Logical block number isrecalculated. By only performing processing on the Logical Block Numbersof the navigational fields, a reduction is required processing power isachieved since less operations are required, and since no processing isperformed on the other entries in the navigation fields nor on the VTSIblock the loss of embedded information is avoided, thus achieving theobjective of the invention.

The invention is based on the realization that by recalculating only theLogical Block Numbers of the navigation fields a VTS block is createdthat is acceptable to recording devices and can easily be handled bythose recording devices when recording. Further more the processing bythe player is also minimal compared to the complete extraction of asection of the data stream and subsequently processing this extractedsection of the data stream in order to recreate an acceptable VTS block

A further embodiment of the invention is characterized in that the firstLogical Block Number of the data file is assigned the value 0.

The recalculation of the Logical Block Numbers of the navigation fieldis required because the reference point for the Logical block number ofthe navigational field is the first Logical Block Number of the datablock. When a section of a VOB block is selected where the first LogicalBlock Number of the section to be transferred does not coincide with thefirst Logical Block of the data block the Logical Block Numbers of thenavigation fields of the section to be transferred will have an offsetwhich must be removed in order to obtain a valid VTS block suitable fortransfer.

The offset can be easily removed with software algorithms well known tothe person skilled in the art by subtracting the Logical Block Number(of the first Logical Block) of the section to be transferred from everyLogical Block Number in the section to be transferred. This effectivelymeans that the first Logical Block Number becomes 0.

The VOB block thus obtained after recalculation of the Logical BlockNumbers is appended to the VTSI block and together form a valid VTSblock.

A further embodiment relating to a method for recording a transfer filecreated using the method as claimed in claim 1, is characterized in thaton a destination rewritable DVD video disc the transfer file is appendedto the end of the data on the destination DVD and a VMG block is updatedto include information on the added transfer file

When recording a transfer file as obtained by the present invention thetransfer file, i.e. VTSI block and VOB block can be directly, withoutprocessing, be appended to the end of the data on the destination discbecause the transfer file is already compliant with the DVD videostandard. The only additional action required for proper recording isthe updating of the VMG area on the DVD disc such that the existence ofthe newly added transfer file is indicated.

A further embodiment relating to a method for recording a transfer fileis characterized in that on a destination rewritable DVD disc containingthe DVD+VR format, the information block comprised in the transfer fileis merged with the VTSI block and the VMG block on the destinationrewritable DVD and the data block comprised in the transfer file isappended to the VOB region on the destination DVD+RW and that theRelative Logical Block Number of each navigation field in the data blockis recalculated relative to a first Logical Block Number of the firstdata block of the VOB region.

This embodiment is based on the same recognition as claim 1, i.e.instead of extracting the data stream and thus losing all embeddedinformation and having to process the data stream from scratch to obtainthe VTSI and VOB blocks suitable for recording the transfer file is onlyprocessed to the extend that the Logical Block Numbers of the navigationfields are recalculated.

It is important to note that the transfer file in this embodiment doesnot have to be the transfer file of claim 1. Any file containing theVTSI block and the VOB block can be processed and made suitable forrecording. As a matter of principle the recalculation can be performedeither after extraction of the section of the data stream but before thecreation of the transfer file, or alternatively a transfer file iscreated without any processing and the processing is performed by therecorder in order to prepare the recording of the section of the datastream. In both cases the amount of processing is reduced compared tothe state of the art, the embedded information is preserved, and data ina format suitable for recording is obtained.

Because the DVD+VR standard requires the Logical Block Numbers to berelative to the first Logical Block Number of the first VOB block in thefirst VTS block, the offset of the navigation fields in the data blockto be recorded must be recalculated in order to reflect the new offset.Since the offset of the Logical Block Number depends on the amount ofLogical Blocks already used on the recording medium, only the recordercan perform this recalculation of Logical Block Numbers of the datablock to be recorded.

The algorithm to implement the offset is well known to the personskilled in the art and essentially consists of the addition of aconstant positive or negative value to every Logical Block Number of thenavigation fields of the data block.

In order to comply with the DVD+VR standard the information block mustbe merged with the VMG block and VTSI block already existing on therecording medium. In this way the presence of the newly added data isindicated on the disc.

A further embodiment relating to a method for recording a transfer filecreated using the method as claimed in claim 1 is characterized in thaton a destination recordable DVD disc containing the DVD+VR format, thedata block comprised in the transfer file is appended to the VOB regionon the destination recordable DVD and the information block comprised inthe transfer file is merged with the VTSI block and the VMG block fromthe destination rewritable DVD and appended to the appended data blockin the form of a VTSI backup block and VMG backup block and that theRelative Logical Block Number of each navigation field in the data blockis recalculated relative to a first Logical Block Number of the firstdata block of the VOB region.

It must be noted that entries are comprised in the VTSI block that alsoneed to be updated, for instance the VTS VOBU Address Map and the VTSCell Address Table.

In the VMGI block there are entries that need to be updated, forinstance the VMGM Cell Address Table and the VMGM VOBU Address Map.

Since the implementations of how to generate these entries, based on theVOBUs obtained via the method of the present invention, is described ingreat detail in the DVD specification a description is not repeatedhere.

The invention will now be discussed based on figures.

FIG. 1 shows the structure of the data on a DVD disc.

FIG. 2 shows the recalculation of the logical block number of thetransfer file according to the invention.

FIG. 3 shows the insertion of the transfer file on a rewriteable DVDdisc with the DVD Video format.

FIG. 4 shows the insertion of the transfer file on a rewriteable DVDdisc in the DVD+VR format.

FIG. 5 shows the insertion of the transfer file on a recordable DVD discin the DVD+VR format.

FIG. 6 shows a play back device comprising the invention

FIG. 7 shows a recorder comprising the invention.

FIG. 1 shows the structure of the data on a DVD disc.

The VTS block 1 comprises a VTSI block 2 and a VOB block 3 and a backupof the VTSI block called the BUP block 4. The VOB block 3 comprises VOBUblocks 5 a. 5 b, 5 c, 5 d. A Vobu 5 a, 5 b, 5 c, 5 d comprises anavigation pack 6 a and one or more video packs 6 b and audio packs 6 c.The navigation pack 6 a comprises a Program Control Information field 7a and a Data Search Information field 7 b. The first entry 8 a in theProgram Control Information field 7 a is the Logical Block Number of theNavigation pack 6 a. The first entry 8 b in the Data Search Informationfield 7 b is the same Logical Block Number of the navigation Pack 6 a.The Logical Block Number in the first field 8 a, 8 b of the ProgramControl Information field 7 a and the Data Search Information field 7 bis expressed relative to the Logical Block Number of the first LogicalBlock of the VOB block.

FIG. 2 shows the recalculation of the logical block number of thetransfer file according to the invention.

The VTS block 25 comprises a VTSI block 20 and a VOB block 21. A section21 of the VOB block 20 is to be copied to a transfer file 26. In orderto accomplish this the logical block numbers of the navigation packs 27c, 27 d, 27 e, 27 f, 27 g have to be recalculated. The resulting newnavigation packs 28 a, 28 b, 28 c, 28 d, 28 e replace the old navigationpacks 27 c, 27 d, 27 e, 27 f, 27 g. the first navigation pack 27 b ofthe section 22 to be transferred is not copied because the first VOBU 29starts at offset 0, i.e. with logical Block Number 0.

In the example given in FIG. 2 the offset to be removed is 400, thismeans that from the logical block numbers of the navigation packs 27 c,27 d, 27 e, 27 f, 27 g an offset of 400 is subtracted. The VTSI block 20must be updated as well since less VOBUs are present and the locationsof the navigation packs 28 a, 28 b, 28 c, 28 d, 28 e is different fromthe original locations of the navigation packs 27 c, 27 d, 27 e, 27 f,27 g. The resulting VTSI block 24 is used to construct the transfer file26. The update of the VTSI block 20 is straight forward, following therequirements of the DVD standard for VTS blocks. For instance in thelist of VOBs, VOBUs and cells the entries for the removed VOBs, VOBUs,and cells must be removed. In the list of navigation packs the entriesfor navigation packs no longer present 27 a, 27 b must be removed andthe entries of the remaining navigation packs 28 a, 28 b, 28 c, 28 d, 28e must be updated to reflect their new locations.

FIG. 3 shows the insertion of the transfer file on a rewriteable DVDdisc with the DVD Video format.

When the VTS block 30 in the transfer file as received by the recorderis to be appended to an existing VTS block 32 in the DVD video format ona DVD+RW disc, the file can be appended, without modification, to theexisting VTS block 32. The VTSI block 31 a of the appended VTS file doesnot need to be changed compared to the VTSI block 30 a of the transferfile 30. The same applies to the VOB block 31 b and BUP block 31 c, nomodification is needed compared to the VOB block 30 b and the BUP block30 c of the transfer file 30.

Also the VTSI block 32 a, VOB block 32 b and BUP block 32 c of theexisting VTS block 32 can remain unchanged. The only modification neededis the update of the VMG block 32 d of the VTS block 32 in order toreflect the appended VTS block 31.

It is self evident that the transfer file can be created by the sourcebefore being put into the transfer file, i.e. before transmission to therecorder, or that a improperly prepared VTS block that was transferredto the recorder can be processed in the recorder using the method of thepresent invention. Having the VTS block in the proper format allows easyrecording of the VTS block, regardless of where the method of thepresent invention was applied.

FIG. 4 shows the insertion of the transfer file on a rewriteable DVDdisc in the DVD+VR format.

When the VTS block 40 in the transfer file as received by the recorderis to be appended to an existing VTS block 41 in the DVD+VR format on aDVD+RW disc, the information in the VTSI block 40 a of the VTS block 40must be merged with the appropriate VTSI block 41 b, 41 c, 41 c of theVTS block 41 on the DVD. The merging consists of adding the entries ineach field of the VTSI block 40 a in the transfer file to thecorresponding entries of the VTSI block 41 b on the DVD. There are threeVTSI blocks 41 b, 41 c, 41 d on the DVD each for a different screenratio and the information from the VTSI block 40 a in the transfer filemust be merged with the VTSI block 41 b, 41 c, 41 d having the samescreen ratio as the VTS block 40 in the transfer file.

In addition the VOB block 40 b of the VTS block 40 in the transfer filemust be appended to the existing VOB blocks 41 e, 41 f, 41 g on the DVD.As a consequence the BUP blocks 41 h, 41 i, 41 j on the DVD must bemoved away from the last existing VOB block 41 g on the disc in order toprovide room for the VOB block 40 b from the transfer file. The VOBblock 40 b from the transfer file is appended to the last VOB block 41 gon the DVD. The BUP blocks 41 h, 41 i, 41 j are then located directlybehind the inserted VOB block. Since the BUP blocks 41 h, 41 i, 41 j arebackup copies of the VTSI blocks 41 b, 41 c, 41 d the updates applied tothe VTSI blocks 41 b, 41 c, 41 d because of the inserted VOB block mustalso be applied to the BUP blocks 41 h, 41 i, 41 j. This can be effectedby applying the update to the BUP blocks 41 h, 41 i, 41 j or by simplycopying the VTSI blocks 41 b, 41 c, 41 d to the location of the BUPblocks 41 h, 41 i, 41 j.

The VMG block 41 a does not need to be updated.

FIG. 5 shows the insertion of the transfer file on a recordable DVD discin the DVD+VR format.

When the VTS block 40 in the transfer file as received by the recorderis to be appended to an existing VTS block 41 in the DVD+VR format on aDVD R disc. The following description will work with both DVD+R andDVD−R discs as long as the disc is not finalized.

The VTS block 50 from the transfer file comprises a VTSI block 50 a anda VOB block 50 b.

The VOB block 50 a of the transfer file is appended to the existing VTSblock 51 on the disc and is shown as the appended VOB block 52 a in FIG.5.

The VTSI block is merged as described for FIG. 4 with the last VTSIblock 51 c on the disc resulting in a merged VTSI block. The VMG block51 b on the disc is updated and appended to the appended VOB block 52 a.The merged VTSI block 52 c is appended to the appended and updated VMGblock 52 b.

When the disc is to be finalized the VMG block 52 b and VTSI block 52 cat the end of the disc are copied to the first section of the disc. Thisis identical to the normal finalization of the DVD−R and DVD+R and iswell documented in the corresponding DVD standards.

The logical block numbers of the navigation packs in the inserted VOBblock 52 a have to be recalculated. The resulting new navigation packsreplace the old navigation packs.

The Logical Block Numbers of the navigation packs must be recalculatedrelative to the reference point of Logical Block Number 0 which is thefirst Logical Block Number of the first VOB block on the disc.

FIG. 6 shows a play back device comprising the invention

The playback device 60 for playing back the data recorded on the recordcarrier 61 comprises the bit engine 62 which is responsible for theprocessing of the code words coming from the record carrier in such away that the extracted code words are suitable for processing by theprocessing means 63. The processing means 63 comprises all means forextracting the VTS information and VOB block from the code wordsprovided by the bit engine 62. For this the processing means 63comprises decoders, buffers, controlling means for controlling thedecoding process, controlling means for controlling the playback deviceand interfacing with the user through a user interface. The elements ofthe processing means are so well known to the person skilled in the artthat they are not shown in FIG. 6 and need no detailed description. Theprocessing means 63 processes the code words and extracts the datastream from the VOB blocks using the information provided by the VTSinformation and information from the VOB blocks. The processing means 63then extracts the data stream in MPEG format from the VTS informationand VOB blocks and provides the data stream in MPEG format to a firstoutput 65 for regular transfer to peripheral devices.

The processing means also provides the VTS information and VOB blocks tothe transfer file creation means 64, which is essentially a processorthat receives the VTS information and VOB blocks and creates a transferfile comprising a modified VTS block and modified VOB block. Thecreation of the transfer file uses the method as explained in FIG. 2. Auniversal file is created where the offset of the navigation packs iscorrected to reflect the new position relative to the beginning of thefile and the VTS information is updated to reflect the new locations ofthe navigation packs and updated reflecting the VOBUs present in the VOBblock. The transfer file thus created is provided to a second output 66for transfer to another device.

FIG. 7 shows a recorder comprising the invention. The recorder 70comprises a first input 75 arranged for receiving a regular MPEG datastream. The regular MPEG data stream is provided to the processing means73 for the creation of VOB blocks and of VTS information in a VTS blockThe VTS block and VOB block are then encoded into code words which areprovided to the bit engine 72. The bit engine 72 processes the codewords provided by the processing means 73 such that they are suitablefor recording on the recording medium 71.

The processing means can also receive VOB blocks and VTS blocks from thetransfer file processing means 74 which is arranged to receive VTSblocks and VOB blocks from a second input 76. The transfer fileprocessing means 74 can accept any VTS block and corresponding VOBblock. The processing of the VTS block and corresponding VOB block isperformed as explained in FIG. 3, FIG. 4 or FIG. 5 depending on the typeof recording medium and video format used in conjunction with therecording medium.

Since the processing is done by the recorder, the VTS block andcorresponding VOB block does not have to be processed according to theinvention before it arrives at the transfer file processing means 74since the transfer file processing means can easily remove any existingoffset and update the VTS block and VOB block accordingly.

Also, because the transfer file processing means is aware of the type ofrecording medium and the video format used the correct measures asexplained in FIG. 3, FIG. 4 or FIG. 5 can be selected for the processingof the received VTS block and corresponding VOB block. The processed VTSblock and corresponding VOB block are then provided to the processingmeans 73 where only the channel encoding has to be applied to obtain thecode words suitable for processing by the bit engine in the regularfashion.

1. Method for creating a transfer file, the file comprising aninformation block comprising information on a data block and the datablock comprising a navigation field and the navigation field comprisinga Relative Logical Block Number of the navigation field, the methodcomprising the steps of creating a transfer file by appending the datablock to the information block characterized in that in the transferfile the Relative Logical Block Number of each navigation field in thedata block is recalculated relative to a first Logical Block Number ofthe data block.
 2. Method for creating a transfer file for transferringa section of a data stream stored in a file as claimed in claim 1,characterized in that the first Logical Block Number of the data file isassigned the value
 0. 3. Method for creating a transfer file fortransferring a section of a data stream stored in a file as claimed inclaim 2, characterized in that the recalculated Logical Block Number isstored in a data search information field and a Program ControlInformation field.
 4. Method for creating a transfer file fortransferring a section of a data stream stored in a file as claimed inclaim 1 characterized in that the section of the data stream comprises aDVD title or a DVD chapter.
 5. Method for creating a transfer file fortransferring a section of a data stream stored in a file as claimed inclaim 1, characterized in that the file comprises one or more VOB blocksin a DVD format
 6. Method for creating a transfer file for transferringa section of a data stream stored in a file as claimed in claim 1,characterized in that the information block is a VTSI block in the DVDformat
 7. Method for creating a transfer file for transferring a sectionof a data stream stored in a file as claimed in claim 1, characterizedin that the data block comprises one or more VOBU blocks in the DVDformat
 8. Method for creating a transfer file for transferring a sectionof a data stream stored in a file as claimed in claim 1, characterizedin that the navigation field is a NV_PCK field in the DVD format 9.Method for recording a transfer file created using the method as claimedin claim 1, characterized in that on a destination rewritable DVD videodisc the transfer file is appended to the end of the data on thedestination DVD and a VMG block is updated to include information on theadded transfer file
 10. Method for recording a transfer file createdusing the method as claimed in claim 1, characterized in that on adestination rewritable DVD disc containing the DVD+VR format, theinformation block comprised in the transfer file is merged with the VTSIblock and the VMG block on the destination rewritable DVD and the datablock comprised in the transfer file is appended to the VOB region onthe destination DVD+RW and that the Relative Logical Block Number ofeach navigation field in the data block is recalculated relative to afirst Logical Block Number of the first data block of the VOB region.11. Method for recording a transfer file created using the method asclaimed in claim 1, characterized in that on a destination recordableDVD disc containing the DVD+VR format, the data block comprised in thetransfer file is appended to the VOB region on the destinationrecordable DVD and the information block comprised in the transfer fileis merged with the VTSI block and the VMG block from the destinationrewritable DVD and appended to the appended data block in the form of aVTSI backup block and VMG backup block and that the Relative LogicalBlock Number of each navigation field in the data block is recalculatedrelative to a first Logical Block Number of the first data block of theVOB region.
 12. Recorder for recording a data stream using the method asclaimed in claim
 9. 13. Play back device for playing a data stream usingthe method for creating a transfer file as claimed in claim 1.